Method and apparatus for washing and grading swarf,for use in the mining or the mineral-oil industry



May 27, 1969 J. SAHORES ETAL 3,446,352

METHOD AND APPARATUS FOR WASHING AND GRADING SWARF, FOR USE IN THE MINING OR THE MINERAL-OIL INDUSTRY Filed Aug. 5. 1966 Sheet o! 2 IN VE/V TORS JEAN SAHORES Jhcpuss Es uEv/N ArTO/P/VEKS 3,446,352 4 RF, FOR BY 1969 J. SAHORES ETAL I METHOD AMD APPARATUS FOR WASHING AND GRADING SWA USE IN THE MINING OR THE MINERAL-OIL INDUST Filed Aug. 5. .1966 Sheet INVEN TOPS Wm m 3mm WE/A United States Patent US. Cl. 209161 9 Claims ABSTRACT OF THE DISCLOSURE In a device for washing and separating solid particles a conical vessel is provided with a discharge valve at its apex, a liquid inlet beneath the valve and a plurality of valved liquid jet inlets disposed above the discharge valve along a portion of the vessel length. The top of the vessel is provided with an overflow trough and beneath the discharge valve and liquid inlet a container is disposed for receiving the sinking solids. Zones of turbulence in an ascending liquid stream are created by the jets and a uniform laminar flow is maintained above the topmost turbulent zone.

The present invention has for an object a method and apparatus for washing and grading swarf, for use in the mining or the mineral-oil industry.

The rocky swarf produced in the operation which is brought to the characteristic indications regarding the nature of the geological layers drilled, if the use of a drilling slurry necessary for evacuating this swarf does not cause its pollution, so that it can no longer serve for geological analysis. This pollution is all the more accentuated and the swarf is all the more thoroughly impregnated as the drilling slurry and the swarf remain intimately mixed until they are separated in decantation tanks.

It has already been proposed to remove samples of swarf and slurry immediately upon leaving the drilling well and to wash the samples in a vertical truncated container which is open at its two ends and supplied at its small-sectioned base by an ascending current of water flowing over the upper edge of said container, and proposals have already been made to grade, by grain size, the constituents of the swarf by gradually diminishing the outflow of the water, the different granulometric fractions of the swarf then being collected in cups which are arranged at the base of the truncated container.

The method and apparatus referred to above do not permit either a rapid and effective washing or a grading of the swarf in well defined granulometric portions or fractions and representing all the swarf contained at the beginning in the sample to be treated. Too weak an ascending outflow of water does not ensure a good washing of the swarf and a disaggregation of the swarf agglomerates, so that on the one hand the badly washed swarf and on the other hand swarf in the form of heterogeneous granulometric portions are found in these collecting cups. In order to produce a better washing of the swarf and a more complete destruction of the swarf agglomerates, it has already been proposed to increase the outflow of water, but in this case, the small swarf is very frequently driven by the current of water and is poured from the container, this obviously falsifying the picture of the mineralogical composition of the drilled rock represented by the swarf. Of course, a predetermined outflow of water can be found which constitutes a compromise between the two extreme outflows of water course of a drilling surface could give 3,446,352 Patented May 27, 1969 and their respective advantages and disadvantages. In any case, the time necessary for washing and granulometrically grading a sample of swarf according to the known method and using the known apparatus is always too long in order to permit, without delay, a possible effective intervention during the carrying out of the drilling operations when the results of the analysis of the swarf are obtained. Moreover, this unacceptably large gap be tween the removal of the sample of swarf and the Washing and granulometric grading of the swarf does not permit the position of the drilled rock, from where said swarf comes, to be located with accuracy. 1

The present invention removes or minimises the above mentioned disadvantages and has for a particular object a method and apparatus for washing and granulometrically grading swarf permitting a sample of a mixture of slurry and a large quantity of swarf to be maintained in suspension in a certain volume of water and permitting the rapid disaggregation of the swarf agglomerates, the complete washing of each particle of swarf on the whole of its surface without the intervention of any moving mechanical member and the strict granulometric grading of the washed swarf.

To this end, the invention consists in a method for washing and grading swarf, comprising the steps of maintaining in suspension a sample of a mixture of slurry and rocky swarf in a vertical ascending current of water whose speed decreases in the downstream or upward direction, eliminating the slurry with the current of water and, collecting the different granulometric portions or fractions of washed swarf on the upstream side of the current of water, and wherein first zones of strong local turbulences are created in the main current of water on the one hand on the upstream side and centrally, and on the other hand, on the downstream side, a second zone is created presenting a uniform laminar ascending flow, recuperating of the different granulometric sections or ranges of swarf, after the slurry has been completely eliminated, by progressively decreasing the local turbulences on the one hand and the outflow of the main current of water on the other hand.

The invention also consists in apparatus for carrying out this method and of the kind comprising a vertical container for washing and grading, which is truncated in shape and whose base is pointed, which is open at its upper end and provided at its lower end with a valve; an evacuation collector provided at the upper end of the container; and a recuperation casing sealed to the lower end of the container, provided firstly with one or more lateral connections which can be connected to a source of pressurized water and secondly with a cup arranged underneath the valve, wherein a plurality of lateral fittings open into the Washing and grading container at least approximately in a perpendicular manner with respect to the axis of this latter, each provided with a closing member and capable of being connected to the same source of pressurized water as the casing.

Using the method and apparatus of the invention, it is possible to effect a rapid and exact sampling of the swarf and to discover in a shorter time the nature of the different geological formations of the ground operated upon by the boring-bit.

Other advantages and characteristics of the present invention will appear from the following description of a number of non-limiting embodiments of the apparatus and the method, said description being made with reference to the accompanying drawings, in which:

FIGURE 1 is a schematic sectional view of a first embodiment of washing and grading apparatus according to the invention,

FIGURE 2 is a schematic sectional view of a second embodiment, the valves controlling flow being omitted for reasons of clarity, and

FIGURE 3 is a schematic sectional view of a third embodiment, wherein the valves controlling flow are again omitted.

The apparatus for washing and granulometrically grading swarf, in its form as is shown in FIGURE 1, comprises a downwardly pointed, generally conical truncated washing and grading container 1 which is open at its upper end and provided with a valve 2 at its lower end. At its upper end, the container 1 is surrounded and surmounted by an evacuation collector 3 whilst at its lower end it is sealed to a recuperation casing 4 having connected thereto one or more lateral connections 5-5 connected to a source of water under pressure, each lateral connection 5, 5' being provided with a closing member or valve V V Near its lower end, above the valve 2, the container 1 is connected to a supply conduit S which is adjustable by a valve V and connected directly to the slurry-evacuating drain of the drilling well. The casing 4 is provided with an unscrewable cover 6 which serves as a support for a cup 7 arranged in said casing 4 underneath the valve 2, which cup is intended to receive the washed swarf.

The container 1 has a certain number of lateral fittings 8, 9 which open out into the container 1 at different levels, the lower lateral fittings 8 being at least approximately perpendicular to the axis of said container 1. Each of these lateral fittings 8, 9 is connected to a source of water under pressure and is provided with a valve or closing member V V At least the zone or the part situated near the upper end of the container 1 is not provided with any lateral fittings. This part is at least to cm. high. Below this part, there is a part or zone provided with the lateral fittings 9, which fittings are inclined with respect to the axis of the container 1 and perpendicular to the wall of the container opposite the opening of the corresponding fitting 9. The fittings 8 are situated in the lowest parts of the container and are preferably horizontal, their axes being parallel in pairs, and opening out into the container 1 on walls which are opposite one another.

The operation of this apparatus is as follows: the container 1 is filled with a predetermined volume of a mixture of slurry and swarf, for example by means of the supply conduit S, the valve 2 and the valves V V for closing the fittings 8, 9 being closed. Then a current of water known as supporting water, whose speed decreases when flowing in an upward direction and which serves to maintain the swarf contained in the slurry-swarf mixture in suspension without an appreciable quantity of swarf overflowing into the collector 3 of the container, is made to circulate through the connections 5, 5, the open valve 2 and the container. Then the valves V V for closing the different fittings 8, 9 are opened, which sends into the main current of water very fine jets of highly compressed water which are capable of cutting up the agglomerates and partially dried slurry. The washing of the swarf is also ensured by these jets of Water. These jets are directed in such a manner that they create in different parts of the container 1 zones of local turbulent flow, the jets crossing one another at a short distance and in this way imposing on the swart which is located in the intermediate space a sort of shearing torque. The whole of the outflow of water entering into the container on the one hand through the valve 2 and on the other hand through the fittings 8, 9 is regulated so that the suspension of the swarf is ensured, so that in the lower and central parts of the container 1 there exist first zones of high local turbulence and so that at least at the upper end of the container there is a second zone whose rate of flow is perfectly laminar. The upper fittings 9, due to their orientation, produce jets of water perpendicular to the wall of the container opposite the opening of the corresponding fitting, against which -wall said jets become refracted. Thus, the formation of the parasitic vertical speed components is avoided. At the same time, by reason of the particular arrangement of the fittings 8, 9, any tangential speed component is also 4 avoided in order to create no rotary movement of the assembly, nor cyclonic operation which could be only harmful because it would facilitate the driving of the fine swarf out of the container 1.

The swarf is violently stirred in the zones of turbulent flow, and the fine particles below a certain range of dimension, adjustable for example between 40 and 300; and determined by the total outflow of water entering the container 1, are evacuated by the current of water flowing at the upper end of the container into the evacuation collector 3.

In the case of the most difllcult swarf to wash, the operation for disaggregating the agglomerates and for washing the swarf are terminated after about 10 minutes. Then the large swarf is seen in the water which has become clear in the container 1, to eddy in the lower part of the container 1, whilst the average and fine swarf swirls in the upper zones of said container.

For the granulometric separation of the swarf, firstly the power of the said disaggregating and washing water jets is reduced, but this does not cause the swarf to deposit. Then one of the connections 5, 5' opening out into the recuperation casing 4 is closed, causing large swarf to drop into these cups 7. Having closed the valve 2 and the second connection 5, the cup 7 is removed from the casing 4 which is accessible through the cover 6. Then another cup has only to be placed underneath the valve 2 and the latter has only to be opened, the rest of the swarf then dropping into said second cup. Of course, if it is desired to obtain more differentiated granulometric ranges, a certain outflow of water corresponding to a finer granulometric range is re-established after the introduction of a new cup and the closing of the casing 4 by the cover 6 and before the opening of the valve 2 As may be seen from FIGURE 2, the washing and granulometric grading container comprises a certain number of truncated parts 10a, 10b, 10c, 10d, alternating with parts of cylindrical form 11a, 11b, 1'10 and 11d. The fittings 8 and 9 are provided on the truncated parts 10a, 10b, 10c and 10d respectively. The upper end of the container is constituted by the cylindrical part 10d. The respective diameters of two cylindrical parts, for example 11b and 11c, situated on either side of a truncated part, for example 100, are respectively equal to the diameters of the lower and upper ends of the truncated part 100.

The embodiment as shown in FIGURE 2 enables a separation to be obtained at very clearly defined washing and grading zones. The conical frusta 10a, 10b, 10c, 10d constitute zones of turbulent flow and of violent stirring, whilst the cylinders 11a, 11b, 11c, 11d constitute zones of laminar flow at uniform speed. These zones of laminar fiow ensure that a large quantity of swarf corresponding to a well determined granulometric portion (function of storage and separation) be maintained in suspension, constitute transition zones between two washing zones intended for different granulometric portions and permit a precise definition of the granulometric cutting of the portions corresponding to the diflerent zones.

In the case of the embodiment shown in FIGURE 2, the container 1 comprises a recuperation casing 4 provided with a plate 12 for supporting a plurality of cups 7, 7', etc. This plate 12 rests for example on a ball bearing 13, is rotatable and may be controlled by means of a drive cylinder 14. The plate 12. is arranged so as to be capable of guiding each of the cups 7, 7' underneath the valve 2. In other words, this plate operates in the manner of a revolver cylinder. The casing 4 also comprises a chamber (not shown) for replacing the cups 7, 7', as well as difierent connections 5, 5, 5" connected to a source of water under pressure.

The operation of this second embodiment is approximately identical to that of the device shown in FIGURE 1. However, in the present case, it is not necessary to close the valve 2 upon the passage of one granulometric portion to another and upon the replacement of a cup 7, 7, etc. This embodiment may advantageously be associated with a clockwork mechanism (not shown) which co-operates with the closing valve V provided in the supply conduit S of the container 1, the diiferent valves (not shown) for closing the fittings 8, 9 and the connections 5, 5', 5", etc. with the valve 2 and the mechanism for driving the plate 12. Of course, this cooperation between the different components and the mechanism is re-established according to a predetermined cycle which can be varied according to needs.

Owing to the vertical dimensions, the different stages, each constituted by a washing zone and a grading zone, sometimes cannot be vertically located one above the other, but instead can be arranged side by side and in cascade (FIGURE 3). In this case, each stage 1a, 1b, 1c, 1d comprises a truncated part a, 10b, 10c and 10d surmounted by a cylindrical part 11a, 11b, 11c and 11d. The upper end of each stage is provided with an evacuation collector 3a, 3b, 3c and 3d, whilst the lower end is secured to a recuperation casing 4a, 4b, 4c and 4d. Each of these casings contains or forms a cup intended to receive the washed and graded swarf. The first casing 4a is connected to a source of water under pressure whilst the other casings 4b, 4c and 4d are each connected to the evacuation collector 3a, 3b, 3c of the preceding stage. The truncated part 10a, 10b, 10c and 10d of each stage 1a, 1b, 1c, 1d is provided with lateral fittings 8, 9, the lower fittings 8 being perpendicular to the axis of the stage, and the upper fittings 9 being preferably perpendicular to the wall situated opposite the opening of the corresponding fitting.

It will be apparent that the invention has been described by way of example only and that various modifications may be made to the specific details referred to without departing from its scope as defined by the appended claims.

We claim: I

1. A method of washing and grading swarf, said method consisting in the steps of:

(a) introducing a sample of a mixture of slurry and rocky swarf into a vertical, columnar container open at the bottom;

(b) introducing a flow of water into the bottom of said columnar container to establish a vertical ascending main current of water whose speed decreases when flowing in the ascending direction, to thereby maintain said sample of a mixture of slurry and rocky swarf in suspension;

(c) creating at least one first zone of local strong turbulences in the ascending main current of water upstream and centrally of said current, by directing very fine jets of high pressure water into said main current;

(d) creating downstream of said first zone at least 1 one second zone presenting a uniform laminar ascending flow, said slurry being separated from the rocky swarf within said first zone and being carried by said ascending current of water into said second zone;

(e) evacuating water and slurry from said columnar container downstream of said second zone; and

(f) recuperating the difierent granulometric portions or ranges of swarf at the upstream end of said main current of water after the slurry has been evacuated by first reducing the power of said high pressure water jets, and then reducing the introduction of water into the bottom of said container, whereby said difierent granulometric portions or ranges of swarf drop out of said container through the open bottom thereof into a recuperation casing mounted therebelow.

2. A method according to claim 1, consisting in the further steps of creating a plurality of said first zones of turbulent flow alternating with said second zones of laminar flow in the main current of water, the zone situated at the downstream end of the main current of water being one of said second zones presenting a laminar flow.

3. A method according to claim 2, wherein a uniform speed of fiow is created in said second zones of laminar flow whilst speeds of fiow which decrease in the downstream direction are efiected in said first zones of turbulent fiow, the zones of laminar and turbulent flow respectively situated downstream of said main current possessing a speed of fiow lower than that existing in the zones of laminar and turbulent flow respectively situated upstream.

4. A method according to claim 1 wherein certain of said jets of high pressure water located upstream are directed into said main current of water at least approximately perpendicularly to the vertical axis of said container, and wherein others of said jets located downstream are inclined with respect to said vertical axis so that they are directed upstream.

5. A method according to claim 1, wherein certain of said jets of water are positioned at the same height on said container and cross one another.

6. A method according to claim 5, wherein said jets of water at the same height are arranged in parallel pairs, the jets of each pair being directed in opposite directions.

7. Apparatus for washing and grading swarf, compris ing: a generally conical vertical washing and grading container truncated in shape and pointed at its base, said container being open at the upper end thereof and being provided at its lower end with a control valve; an evacuation collector provided at the open upper end of said container for receiving liquid overflowing said upper end; a recuperation casing sealed to the lower end of said container below said control valve, and provided with one or more connections laterally thereof, said connections being connected through valve means to a source of water under pressure; cup means arranged below said control valve within said recuperation casing; a first plurality of lateral fittings on a lower, first conical portion of said container, said first lateral fittings opening into said container and being arranged with their axes at least approximately perpendicular to the vertical axes of said container, each of said first lateral fittings being connected through valve means with a source of water under pressure; a second plurality of lateral fittings on an upper, second conical portion of said container, said second lateral fittings opening into said container and being arranged with the axis of each generally perpendicular to the facing conical wall of said second conical container portion, each of said second lateral fittings being connected through valve means to a source of water under pressure, said second conical container portion being spaced downwardly from the upper end of said container; and supply conduit means arranged to supply material to be washed and graded to the lower end of said container between said first conical portion and said control valve.

8. Apparatus according to claim 7, wherein said first and said second conical portions of said container are separated by a third container portion having no lateral fittings thereon.

9. Apparatus according to claim 8, wherein said third container portion between said first and said second conical container portions is cylindrical.

References Cited UNITED STATES PATENTS 664,712 12/1900 Baldenebro 209-161 1,133,721 3/1915 Gregg 209- 1,147,356 7/1915 Allen 209-160 1,966,609 7/ 1934 Chance 209-1725 2,361,207 10/1944 Horsfield 209160 FOREIGN PATENTS 9,135 1841 Great Britain.

FRANK W. LUTTER, Primary Examiner. 

